Reversing means for percussion hammers



Sept. 27, 1966 w. scHRTTLE REVERSING MEANS FOR PERCUSSION HAMMERS FiledMarch 16, 1964 United States Patent O 2 claims. (ci. 173-110) Thepresent invention relates to percussion tools and is particularlyconcerned with a percussion hammer or drill provided with a toolreversing or turning arrangement; Hammers of this type `are employed forground breaking operations, chisel, caulking` or cutting work, inunderground work as well as in building construction work.

The percussion or beating system of hammers of this type comprisesessentially a percussion piston guided for axial movement and iirmlyconnected for force transmission with the driving elements and whichacts on the insert end or shank of the tool.

A hammer of this type can also be used as a boring or drilling hammerfor boring in natural rock, artiiical rock, concrete or masonry work,when it is equipped with a boring chisel.

However, when a percussion hammer is inserted as the boring tool, it isnecessary to continually turn the tool manually, with the result thatthe turning speed remains relatively low in relation to the high numberof blows of a percussion hammer. Without reversing or turning, thechisel encounters the same notch or score for each blow so that noboring eiect is obtained. The manual turning becomes particularlydiliicult when drilling is effected with a beating or blow hammer in ahorizontal or overhead direction.

A boring or drilling hammer is also known which has a turning meanswhere the turning takes place evenly during the entire operating time.However, this turning means has the shortcoming that the turningmovement would have to take place at the time the tool is applied, i.e.,when it is being seated in its notch. Here the overload is disconnectedas a result of the blocked turning tendency of the boring chisel bymeans of sliding clutches and other safety locking means. Thecomplicated construction of such a turning device` necessarily makes thedevice particularly prone to jam, it increases wear and also expense.

To overcome the shortcomings the invention provides a device whicheffects the turning of the boring chisel completely automatically.Accordingly the invention provides a motor driven percussion and boringhammer provided with a tool turning device wherein a toothed disk whichis secured to a reciprocating sleeve can be raised relative to andsimultaneously turned with a toothed disk formed on a tool guidingsocket.

The particular advantages and structural details of the invention willbecome apparent from the following speciiication with reference yto theaccompanying drawings in which:

FIG. 1 illustrates a percussion drill hammer equipped with the device inaccordance with the invention, and

FIG. 2 is a side view of a portion of the hammer illustratingparticularly the sleeve with the guide slot.

The embodiment of the invention illustrated in theV drawings comprises alower housing portion 1 adapted to accommodate the entire mechanismincluding the power supply means, a percussion piston 2 to the lower endof which is secured a reciprocating sleeve 3. Sleeve 3 is provided witha downwardly extending riding groove 4 in the wall thereof and has atoothed disk 5 at its "rcel lower end. A driving pin 6 extends throughthe rifling groove or slot 4 of the reciprocating sleeve 3 into astraight guide groove 7 of the housing 1 which secures the percussionpiston 2 against turning.

The percussion drill has a handle 10 secured to the housing 11 of thetool and provided with a switch 12 which when operated actuates theelectromotor 13. The motor 13 is journalled in bearings 14, 15 and has atoothed gear 16 which meshes with and drives a bevel gear 17. Bevel-gear 17 is secured and journalled in bearings 18, 19. A pin 20 issecured to the bevel gear 17 to which a connecting rod 22 is secured bymeans of a bearing 21. The connecting rod 22 is linked by means of apivot pin 23 to a guide piston 24.

The guide piston 24 and a guide rod 25 are operative to drive anoscillating spring system which comprises a helical spring 26 and aplurality of disk or cup springs 27, 28, 29. The nests of springs aredisposed in a percussion piston 30 which extends for reciprocatingmovement axially of the lower housing portion 1. Springs 26, 27 aresupported `at the bottom against the bottom 2 of the percussion piston30 by way of spring plate 31 or against the collar 32 of the guide rod25. At the top the spring assembly 26, 27 is biased against the springassembly 28, 29 or the glide piston 24. The upper spring assembly 28, 29is held on the one hand by the upper spring ring 33 and on the otherhand by the shoulder 34 in the percussion'piston 30, respectively, thelower spring assembly 26, 27. An intermediate ring 35 is providedbetween springs 28 and 29 which serves as a guide for the guide piston24 and as a spacing ring for the disk springs 28, 29.

During each up or down movement of the percussion piston 2 the driver orpin 6 which extends through the rifle slot 4 and is secured againstrotation in the straight guide groove 7 imparts a reciprocating rotarymovement to the reciprocating sleeve 3, whereby during each upwardthrust of the percussion piston 2 the axial component of force effectssimultaneously the raising of the reciprocating sleeve The toothed disk5 secured to the bottom of the reciprocating sleeve presents teethextending in the direction of the percussion piston 2. The opposite orcounter member for this is formed by a toothed disk 8 arranged withinthe reciprocating sleeve 3. This toothed disk 8 is formed on the toolguiding socket 9 and rotatable therewith but is not axiallydisplaceable.

By raising the reciprocating sleeve 3 during each upward movement of thepercussion piston 2, the two oppositely disposed toothed disks I5 and Scome into engagement, so that with each rotation of the reciprocatingsleeve 3 also a rotation of the tool guiding socket 9 is effected, theangle of rotation of which depends on the length of the rie slot `4 andon its inclination with respect to the longitudinal axis of thereciprocating sleeve 3.

During the downward movement of the percussion piston 2 thereciprocating sleeve 3 is turned back through the same angle, butsimultaneously a force rbecomes eiecti-ve in a 'vertically downwarddirection which separates the toothed disk 5 which is connected with thereciprocating sleeve 3 from the toothed disk '8, so that the toolguiding socket y9 does not follow the return rotational'movement of thereciprocating sleeve 3.

Having now described my invention with reference to the embodimentillustrated in the drawings, I do not wish to be limited thereto, butwhat 'I desire to protect by Letters Patent of the United States is setforth in the appended claims.

I claim:

1. A power driven percussion hammer and drill of the type provided witha tool turning means and comprising a housing, said tool turning meanscomprising a reciprocating sleeve arranged in the lower end of saidhousing, a first toothed disk provided on the lower end of said sleeve,a tool guiding socket disposed in the lower end of said housing, asecond toothed disk provided on said socket and disposed opposite saidrst toothed disk and means for raising said iirst toothed disk to engage'and turn with said secondrtoothed disk, said means comprising apercussion piston having a driver pin and said sleeve being in forcetransmitting relation with said piston and having a rifle slot receivingsaid driver pin for reciprocating movement therein for turning Vsaidsleeve and said lfirst toothed Y disk. e

2. `A power driven percussion hammer and drill of the type provided witha tool turning means and comprising a housing, said tool turning meanscomprising aereciproeating sleeve arranged in the lower end of saidhousing, a irst toothed ydisk provided onthe lower end of said sleeve, atool guiding socket disposed inthe lower end of said housing, a secondtoothed disk provided ori said socket and disposed opposite said` irsttoothed disk and means for raising said first toothed disk to engage andturn with said second toothed disk, said means comprising a percusdriverpin extending into said guide groove for straight line movement therein.e

References Cited by the Examiner UNITED STATES` PATENTS 1,244,38610/1917 spehar 1731+110 2,028,252 1/1936 slaterY 173-109 2,791,909y5/1957 Riek 74.-89 2,944,431 7/1960 Dexter 74-89 FOREIGN. PATENTS347,355 1/1922l Germany. 688,917 12/1938.- Germany.

FRED C. MATTERN, Jg., Primary Examiner. L. P. KESSDER, AssistantExaminer.

1. A POWER DRIVEN PERCUSSION HAMMER AND DRILL OF THE TYPE PROVIDED WITHA TOOL TURNING MEANS AND COMPRISING A HOUSING, SAID TOOL TURNING MEANSCOMPRISING A RECIPROCATING SLEEVE ARRANGED IN THE LOWER END OF SAIDHOUSING, A FIRST TOOTHED DISK PROVIDED ON THE LOWER END OF SAID SLEEVE ATOOL GUIDING SOCKET DISPOSED IN THE LOWER END OF SAID HOUSING, A SECONDTOOTHED DISK PROVIDED ON SAID SOCKET AND DISPOSED OPPOSITE SAID FIRSTTOOTHED DISK AND MEANS FOR RAISING SAID FIRST TOOTHED DISK TO ENGAGE ANDTURN WITH SAID SECOND TOOTHED DISK, SAID MEANS COMPRISING A PERCUSSIONPISTON HAVING A DRIVER PIN AND SAID SLEEVE BEING IN FORCE TRANSMITTINGRELATION WITH SAID PISTON AND HAVING A RIFLE SLOT RECEIVING SAID DRIVERPIN FOR RECIPROCATING MOVEMENT THEREIN FOR TURNING SAID SLEEVE AND SAIDFIRST TOOTHED DISK.